This invention relates to radiography and to problems encountered in positioning a patient in relation to X-ray equipment and in relation to photographic film or digital media adapted for taking an X-ray picture of a portion of the patient.
Patients that are severely ill or are suffering from spinal or pelvic injury are often presented to a radiographer lying upon a bed or other support. In order that an X-ray image may be taken, the photographic film or digital medium, conventionally mounted in an X-ray cassette (together with a radiographic grid when the chest, spine or pelvis are to be imaged) must be positioned beneath the patient so that the patient can be placed beneath a source of X-rays to enable an X-ray image to be taken through a portion of their body.
Specially adapted beds or supports have previously been provided with a hollowed out section into which the radiographic grid and X-ray cassette may be inserted while the patient is lying upon the support. However, this is not satisfactory in use since the patient must first be transferred to the special support on which he will not be adequately supported at least at the time that the grid and cassette are being inserted from the side beneath him. Attempts to simply insert the grid and cassette, either alone or within a pouch, from the side and beneath the patient between an upper and a lower sheet on a conventional bed or support have also not proved satisfactory, firstly because of the friction encountered and secondly because of the jarring effect of the edge of the grid and cassette on the patient's spine or pelvis. X-ray cassettes for taking a chest or pelvic X-ray image and associated radiographic grids are quite substantial. The resultant image has dimensions of the order of 35 cm×43 cm, the orientation depending upon whether the image is taken in landscape or portrait format. The grid and cassette are slightly larger but known to radiographers as a “35×43” grid and cassette. The grid and cassette have a thickness of around 25 mm.
The patent literature includes a number of proposals for mounting X-ray cassettes from or within supports slid into position beneath a patient, but none is ideal. Thus: Wright in U.S. Pat. No. 5,703,925 proposes a support for an X-ray cassette that in use is positioned between a raised patient support platform and smooth flush surface below the patient support platform. A spade supports an x-ray cassette and is enabled to slid on this flush surface. Strawder (U.S. Pat. No. 5,226,068) employs a support to mount an X-ray cassette in a vertical position alongside a patient. The support is generally flat apart from a cavity enabling the cassette to stand upright on edge from the support and a ramp edge enabling the support to be more easily slid under a patient. Möller proposes a lifting device in U.S. Pat. No. 5,133,000 to raise a bed to slide an X-ray cassette beneath it. Waerve (U.S. Pat. No. 4,247,778) has a generally flat X-ray cassette chamber with a rounded leading edge to ease its insertion beneath a patient. An X-ray cassette can be moved within the chamber to enable an X-ray to be taken vertically through the patient in one configuration or horizontally through the patient in another configuration.